Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)

Kováts, D. ; Stieber, J.: Some observations on the dynamism of structural development in the stem-borne root of Lithospermum purpureo-coeruleum L.

Plate VI. Cross-sections of older root; separation process of primary cortex. Fig. 41: Intense division of pericambial zone followed by division of endodermal cells, thus forming a secondary endoderm (xl20); Fig. 42: Anticlinally divided endodermal cells, with indented cell walls toward central cylinder ( x260); Fig. 43: Primary cortex separating from central cylinder ( x 30); Fig. 44: After separation of primary cortex root covered by cells of secondary endoderm, then they also slowly wear off ( X 195). — Cross and longitudinal sections of older root, sclerotic pith. Fig. 45 : Secondarily strongly incrassate xylem cylinder, medially with sclerotic pith parenchyma cells; polyarchally situated procambium bundles discernible; root covered by secondary endoderm cells (x80); Fig. 40: Sclerotic pith marginally with 5-6 procambium bundles ( x 115); Fig. 47: Longitudinal section of trachea thickened by bordered pits, surrounded by fibres and sclerotic pith parenchyma cells, their walls thickened by simple pits ( x 260) ; Fig. 48: Longitudinal section of tracheae, their walls thickened by bordered pits, in xylem of old root ( x 410). Plate VII. Cross and longitudinal sections of old root. Fig. 49 : Trachea member, its wall thickened by alternating bordered pits, and its perforation in xylem of old root ( x330); Fig. 50: Multiseriate periderm of several years old root (cross-section, X 260) ; Fig. 51 : More or less ring-porous, xylem with annual rings, multiseriate cambium, phloem and periderm of 4-5 years old root ( x 50) ; Fig. 52: More or less ring-porous, xylem of several years old root with annual rings ( X 150);—Cross­sections of roots, secondary endoderm. Fig. 53: Pentarchal structure of cambium, medially with pith parenchyma; wall of endodermal cells already strongly incrassate ( x 150); Fig. 54: Procam­bial bundles in tangential position, xylem ring under development; no waved cambium formed; endoderm becoming secondary by thickening of its cell walls (xl20); Fig. 55: Thick-walled endoderm cells; no waved cambium formed as yet (x260); Fig. 56: Differentiated tetrarchal procambium; endodermal cells already secondary, their walls incrassate ( X 150). All photographs original. Authors' addresses: Dr. J. STIEBER Institute for Applied Botany and Histogenetic University Budapest Budapest, VIII., Múzeum krt. 4/a Hungary D. KOVÁTS Botanical Department Hungarian Natural History Museum Budapest, XIV., Vajdahunyadvár H ungar y \

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